They were lounging on a beach in Greece with their swimmers on. The caption for the post read, "Rockin' with my shoalmates."

She followed it up with another picture of her and Sam swimming in the sea, with the caption, "O hi! We're having a whale of a time!! We saw a sea turtle!! She was pure magic and filled me to the brim with joy!! (See my face for further details.)" A few turtle emojis were peppered in there as well to further express her, uh, enthusiasm.

While Sam isn't particularly active on social media himself, brother Arthur is more impartial to the occasional snap – especially if it's a shirtless one.

The youngest Chatto brother posted a pic of himself by the sea with the caption, "There are worse places to have glandular fever."

It's hard to believe this is the same person who was page boy to the Queen in 2012. Time flies!

(Getty)

Both brothers are attending Edinburgh University, with Sam having just recently graduated.

The last royal engagement the Chatto brothers attended was Meghan and Harry's wedding in May. They showed up with their mother, Lady Sarah, and father Daniel, and both posted on their Instagram accounts to celebrate the happy couple.